The present invention relates to improvements in heat sinks for electronic components, and, in one particular aspect, to unique resilient sheet-metal heat dissipators of low-cost construction which will close to maintain firm intimate heat-transfer engagements with thermally-conductive tabs or module bodies while being readily openable to admit or release such tabs or bodies without difficulty and with little likelihood of component damage.
As is well known at the current stage or developments in the art, applications of miniature semiconductor devices and microcircuit modules are severely limited in respect of the self-generated heat which they can successfully expel and prevent from building up as they are caused to operate at higher and higher powers. In some instances, the environments of use permit elaborate forced-liquid cooling systems to be employed, but a very common and economical expedient instead involves the attachment of small finned metal extrusions or stampings which help to conduct and radiate heat away from the thermally-vulnerable regions. To further the latter purposes, encapsulated devices or component packages are sometimes provided with exposed heat-transfer parts, such as flat broad-area tabs or plates, which promote thermal-energy transfer to such attachments and thence convectively away into the ambient environment along both its sides. The heat-dissipating attachments intended for use with such heat-transfer parts may include a thin resilient spring clip member cooperating with a rigid and more massive member (as in U.S. Pat. No. 3,548,927), or it may consist of a single stamped sheet-metal body shaped both to promote cooling and to grasp and hold itself in place on the heat-transfer part (U.S. Pat. Nos. 3,893,161 and 4,041,524 and 4,054,901).
Ease and convenience of fitting heat-sink attachments are important factors, as are, also, the creation and maintenance of broad-area heat-exchange pathways between the heat-transfer parts and their attachments. However, when auxiliary fasteners, clips and tools must be used, the fastening operations can become awkward, and, when either auxiliary or integral clipping arrangements are exploited, their designs may cause essentially line-contacting or small-area contacting to occur where one would instead prefer to develop broader contact areas for maximum heat transfer. If intimate tightly-sprung broad-area regions of clamping are instead designed into a heat-sink, it may then be difficult to fix in place or may be impossible to apply without high risk of damage to a device, such as a microcircuit module, whose body and/or numerous leads may be susceptible to injury by large clamping forces. In accordance with the present teachings, such limitations are avoided in heat-sink attachments of low-cost construction which open to admit heat-transfer tabs or modules readily and with reduced likelihood of damage and which are easily snapped to self-fastened closure with broad-area contacting promoting efficient transfer of heat.